KISSIMMEE, Fla. -- The Osceola County Health Department is investigating an outbreak of chickenpox at an elementary school, according to health officials.

Officials said more than 20 children at Mill Creek Elementary School in Kissimmee have been diagnosed with the Varicella illness.

More children are likely to be affected and this has the potential to spread to other schools and ages in Osceola County, according to a health department release.

The Florida Department of Health is recommending vaccinating the children at Mill Creek Elementary who have never received the Varicella vaccine and never had chicken pox or have received only one dose of the vaccine.

The Osceola County Health Department will be offering vaccinations to the students at Mill Creek Elementary School on Thursday.

Chickenpox is an infectious disease caused by the varicella-zoster virus, which results in a blister-like rash, itching, tiredness, and fever.

In unvaccinated children, chickenpox most commonly causes an illness that lasts about 5-10 days.

Children usually miss 5 or 6 days of school or childcare due to their chickenpox and often have symptoms such as fever, severe itching, an uncomfortable rash, and dehydration or headache. Serious complications from chickenpox include bacterial infections which can involve many sites of the body including the skin, tissues under the skin, bone, lungs (pneumonia), joints, and blood.

Pregnant women and children who have a serious medical condition are advised to consult their primary care physician about possible exposure.

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